Есть две сетевухи, периодически обе из них (не обе сразу, а по-отдельности) начинают блокировать пакеты:
eth5 Link encap:Ethernet HWaddr __:__:__:__:__:__
inet addr:___.__._.___ Bcast:___.__._.___ Mask:___.___.___._
inet6 addr: fe80::___:____:____:____/__ Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:7956410 errors:362 dropped:7006 overruns:0 frame:266
TX packets:5667389 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:383653173 (365.8 MiB) TX bytes:1494681476 (1.3 GiB)
Interrupt:10 Base address:0xe000
eth4 Link encap:Ethernet HWaddr __:__:__:__:__:__
inet addr:___.___._._ Bcast:___.___._.___ Mask:___.___.___._
inet6 addr: fe80::___:____:____:___/__ Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:13876295 errors:1838 dropped:3150 overruns:0 frame:1203
TX packets:23960527 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:1978344789 (1.8 GiB) TX bytes:3757855714 (3.4 GiB)
Interrupt:11 Base address:0xe100